EOL_HF
EOL Raw data: January 2018 to December 2022
Gaps:
- 21 Mar to 17 May 2019.
- 22 to 24 Nov 2022
NAs:
- No NAs for T
- NAs for S, O, AOU
Anomalies method
By months
| Slope | SE Slope | P Slope | Intercept | SE int. | P int. | F | df | R2 | P value | |
|---|---|---|---|---|---|---|---|---|---|---|
| temp_ano | 0.0322404 | 0.0040676 | 0 | -65.14189 | 8.218505 | 0 | 62.8254 | 39938 | 0.0015706 | 0 |
| sal_ano | 0.0263224 | 0.0007535 | 0 | -53.18294 | 1.522422 | 0 | 1220.3225 | 39008 | 0.0303349 | 0 |
| oxy_ano | -1.4649535 | 0.0270565 | 0 | 2959.86194 | 54.666168 | 0 | 2931.6077 | 39007 | 0.0699024 | 0 |
| aou_ano | 1.3467183 | 0.0230785 | 0 | -2720.97387 | 46.628895 | 0 | 3405.1692 | 39007 | 0.0802876 | 0 |
Temperature
Salinity
Oxygen
AOU
By days
| Slope | SE Slope | P Slope | Intercept | SE int. | P int. | F | df | R2 | P value | |
|---|---|---|---|---|---|---|---|---|---|---|
| temp_ano_day | 0.0338983 | 0.0030054 | 0 | -68.49171 | 6.072406 | 0 | 127.2198 | 39938 | 0.0031753 | 0 |
| sal_ano_day | 0.0250891 | 0.0006957 | 0 | -50.69120 | 1.405572 | 0 | 1300.6450 | 39008 | 0.0322671 | 0 |
| oxy_ano_day | -1.4609430 | 0.0241975 | 0 | 2951.75892 | 48.889779 | 0 | 3645.2375 | 39007 | 0.0854642 | 0 |
| aou_ano_day | 1.3550905 | 0.0222610 | 0 | -2737.88944 | 44.977167 | 0 | 3705.5087 | 39007 | 0.0867546 | 0 |
Temperature
Salinity
Oxygen
AOU
Results from anomaly methods (month and day) are similars with a slight improvement in SD.
Other methods:
By autocorrelation + decompose function or Mann-Kendall : not possible because of gaps
–> Filling gaps.
Moving average
Temperature
No gaps to fill.
##
## Call:
## lm(formula = y ~ x, data = reg_val_ts_temp_eol_less_season)
##
## Residuals:
## Min 1Q Median 3Q Max
## -11.2904 -2.1147 -0.1173 1.5592 10.5261
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 18.49114 0.04911 376.51 <2e-16 ***
## x 0.18173 0.01390 13.07 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 3.655 on 39938 degrees of freedom
## Multiple R-squared: 0.004259, Adjusted R-squared: 0.004234
## F-statistic: 170.8 on 1 and 39938 DF, p-value: < 2.2e-16
Slope is 0.182. Means that periode of 5 years is not suitable. Slope not reliable.
Salinity
##
## Call:
## lm(formula = y ~ x, data = reg_val_ts_sal_eol_less_season)
##
## Residuals:
## Min 1Q Median 3Q Max
## -3.02197 -0.12426 0.03126 0.14767 0.53884
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 3.791e+01 2.440e-03 15532.81 <2e-16 ***
## x 1.005e-04 2.432e-06 41.31 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.2436 on 39938 degrees of freedom
## Multiple R-squared: 0.04098, Adjusted R-squared: 0.04095
## F-statistic: 1706 on 1 and 39938 DF, p-value: < 2.2e-16
Slope is 0. Means that periode of 5 years is not suitable. Slope not reliable.
Oxygen
##
## Call:
## lm(formula = y ~ x, data = reg_val_ts_oxy_eol_less_season)
##
## Residuals:
## Min 1Q Median 3Q Max
## -65.320 -15.280 1.126 15.024 44.776
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 2.417e+02 1.852e-01 1305.08 <2e-16 ***
## x -7.905e-03 1.846e-04 -42.82 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 18.49 on 39938 degrees of freedom
## Multiple R-squared: 0.0439, Adjusted R-squared: 0.04388
## F-statistic: 1834 on 1 and 39938 DF, p-value: < 2.2e-16
Slope is -0.008. Means that periode of 5 years is not suitable. Slope
not reliable.
AOU
##
## Call:
## lm(formula = y ~ x, data = reg_val_ts_aou_eol_less_season)
##
## Residuals:
## Min 1Q Median 3Q Max
## -34.302 -6.017 0.323 6.586 38.208
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -1.348e+01 8.602e-02 -156.74 <2e-16 ***
## x 3.861e-03 8.572e-05 45.05 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 8.588 on 39938 degrees of freedom
## Multiple R-squared: 0.04835, Adjusted R-squared: 0.04833
## F-statistic: 2029 on 1 and 39938 DF, p-value: < 2.2e-16
Slope is 0.004. Means that periode of 5 years is not suitable. Slope not reliable.
Mann-Kendall
The function kendall.SeasonalTrendTest returns estimated values of Kendall’s τ, the slope, and the intercept for each season, as well as a single estimate for each of these three quantities combined over all seasons. The overall estimate of τ is the weighted average of the p seasonal τ’s
The overall estimate of slope is the median of all two-point slopes computed within each season.
The overall estimate of intercept is the median of the p seasonal estimates of intercept.
The Kendall Tau, or Kendall rank correlation coefficient, measures the monotony of the slope. Kendall’s Tau varies between -1 and 1; it is positive when the trend increases and negative when the trend decreases.
The Sen slope, which estimates the overall slope of the time series. This slope corresponds to the median of all the slopes calculated between each pair of points in the series.
The significance, which represents the threshold for which the hypothesis that there is no trend is accepted. The trend is statistically significant when the p-value is less than 0.05.
Results:
Temperature
## tau slope intercept
## 0.04282142 0.04045000 36.35810833
Salinity
## tau slope intercept
## 0.1023034 0.0199750 -27.4444783
Oxygen
## tau slope intercept
## -0.1107562 -1.1655297 732.7343833
AOU
## tau slope intercept
## 0.1704564 1.5167524 -2653.5551529
Results from Mann-Kendall and anomalies (by day) are similars.